2010 Highlights

001-026_Pres_High_Annual Report_2009 template 7/12/11 9:59 AM Page 6 from the 2010 Annual Report Highlights of the Year Research Research at Cold Spring Harbor Laboratory (CSHL) has a major impact in the areas on which our principal investigators focus: cancer, neuroscience, plant biology, and quantitative biology. It has often been noted that our influence is especially remarkable for an institution of CSHL’s compar- atively small size. A recent survey by the respected science publisher Thompson Reuters in fact placed CSHL first in a group of 20 “heavy hitters” in molecular biology and genetics, selected from among 42,000 research institutions worldwide. During the first decade of the 21st century, research papers based on work conducted in CSHL laboratories had more impact—as measured by their frequency of citation by peers—than papers originating in any other institution, including the Mas- sachusetts Institute of Technology, the Salk Institute for Biological Studies, Memorial Sloan-Ket- tering Cancer Center, The Rockefeller University, and Harvard University. This survey is not the only measure of our worth or that of any institution, but it does suggest the power of the work being performed at CSHL and its relevance, as measured by those who use it—our colleagues at laboratories throughout the nation and across the globe. Together, we are en- gaged in a vital enterprise, in which we bring all of our intellectual skills and technical ingenuity to bear on fundamental questions of biology and generate knowledge that forms the basis for biomed- icine to move forward in its mission to relieve the major causes of human suffering. Below, we sum- marize just a few of the many fascinating and important findings made by CSHL’s dedicated team of investigators during 2010. Antisense Therapy Reverses Spinal Muscular Atrophy in Mice Professor Adrian Krainer achieved a milestone this past year in his continuing effort to understand spinal muscular atrophy (SMA), the leading genetic cause of death in infants. SMA is the result of mutations in the survival of motor neuron 1 (SMN1) gene. These lead to abnormally low levels of SMN protein in motor nerve cells of the spinal cord and to the degeneration of those cells. Last year, Adrian and colleagues identified a compound that stimulates SMN production by altering RNA splicing. This year, they carried the work an important step further: By introducing chemically modified pieces of RNA called antisense oligonucleotides (ASOs) into the spinal cords of mice, they succeeded in reversing symptoms of Type III SMA. This result exemplifies how superb A. Krainer basic science—in this case, work in the Krainer lab on the cell’s splicing machinery—can be fertile ground for value-added science, the kind of research activity that adds commercial value to fundamental discoveries. Krainer’s team has collaborated with scientists at Isis Pharmaceuticals in designing and synthesizing ASOs, which can be designed to bind to any piece of RNA. The team ze- roed in on an ASO that optimally enhanced the inclusion of an exon that in people with SMA is “skipped” by cellular machinery that cuts and pastes bits of RNA “message” together to form a template for protein manufacture. A particularly encouraging aspect of the team’s progress this year was learning how to overcome barriers to delivering ASOs directly into the fluid that surrounds the brain and spinal cord. The treatment’s therapeutic effect in mice persisted for half a year after it was discontinued, indi- cating that the ASO is very stable. In addition, the team reported no inflammation or toxicity. Reversing Alzheimer’s-like Memory Loss in Drosophila Work published this year by Professor Yi Zhong’s team demonstrated a means of reversing memory loss in fruit flies caused by brain plaques similar to those implicated in Alzheimer’s disease. Modeling a complex human illness such as Alzheimer’s is an important goal of basic science, and the fly pro- 6 001-026_Pres_High_Annual Report_2009 template 7/12/11 9:59 AM Page 7 Highlights of the Year 7 vides us with a suitably simple starting point. The fly brain should not be underestimated, for in it we see significant conservation of DNA sequence found in human genes known to affect the structure and function of neural networks. Protein fragments of the β-amyloid molecule associated with Alzheimer’s are known to alter many cell-signaling proteins such as phosphoinositol-3 kinase (PI3K), causing a wide range of neuronal dysfunctions. In flies engineered to produce the human β-amyloid protein in their brains, Yi’s team set out to better comprehend the molecular basis of memory loss. This yielded a finding that went against received wisdom that attributed a protective role to the kinase. Yi’s team instead found that the increased PI3K activity caused a type of neurotransmission that is patho- logically enhanced when β amyloid is present in the fly brain. Injection of chemicals that Y. Zhong block the kinase’s action and separate efforts to turn off the gene that encodes it both had the effect of restoring normal signals in the fly brain. This research also intriguingly suggests that brains affected by Alzheimer’s might become insulin resistant because of elevated PI3K activity. Thus, the kinase becomes a potential target for novel therapeutics. A Possible Inflammatory Component in Resistance to a Targeted Lung Cancer Drug A critical question about cancer concerns the molecular mechanisms involved in resistance to chemotherapy. Particularly vexing is the phenomenon of resistance to the best drugs developed to date, so-called targeted therapies. Assistant Professor Raffaella Sordella’s lab this year shed new light on resistance to Tarceva (erlotinib), a targeted therapy approved in 2004 for a subset of patients with non-small-cell lung cancer (NSCLC) and for some patients with pancreatic cancer. Tarceva’s molecular target is known—the cell membrane receptor called epidermal growth factor receptor (EGFR)—as are processes that lead to about half of observed cases of resistance. But what about the other 50%? Raffaella and colleagues from Weill Cornell Med- ical College and the Boltzmann Institute in Vienna discovered a subpopulation of NSCLC cells that are intrinsically resistant to Tarceva. These tumor cells were observed to secrete elevated amounts of a growth factor called transforming growth factor-β (TGF-β), which in turn increases secretion of interleukin-6 (IL-6), an immune signaling molecule. Signif- icantly, these effects were independent of the EGFR pathway. The team therefore hypoth- esizes that inflammation is one of the factors that can render a tumor cell resistant to treatment with Tarceva. R. Sordella A Protein Linked to Leukemia “Bookmarks” Highly Active Genes in Dividing Cells When CSHL Fellow Christopher Vakoc and colleagues demonstrated this year how so-called epigenetic instructions are stably transferred from one generation of cells to the next, they provided a compelling explanation of how a protein called MLL (mixed lineage leukemia) may be involved in triggering leukemia. During cell division, gene activity is normally shut down temporarily. The dividing cell’s chromosomes condense and expel most of the proteins that cling to them, which are called epigenetic marks. These marks at other times in the cell cycle help to determine which genes are accessible to the cellular machinery and can be expressed and which genes are inaccessible and cannot be expressed. Unlike most other chromosome-bound epigenetic marks, Chris’ team found that the MLL protein stays teth- ered to the genetic material during cell division. It acts as a “bookmark,” preserving a bit of vital gene expression information. But as the cell divides, sometimes the MLL proteins shift to new locations on the chromosome. Interestingly, they seem to attach to genes that are the most active before cell division shuts down all gene activity. This, in turn, can draw C. Vakoc 001-026_Pres_High_Annual Report_2009 template 7/12/11 9:59 AM Page 8 8 Highlights of the Year other proteins to the same area, with the net effect of jump-starting gene expression. Chris is now studying how MLL mutations might promote the abnormal proliferation of cells in leukemia. A Potential Way to Reverse Cancer Cell Metabolism and Tumor Growth Eighty years ago, Nobel laureate Otto Warburg observed the altered metabolic state of cancer cells and tried to connect it, biochemically, with processes that give rise to the rapid proliferation that characterizes cancer. In particular, cancer cells are distinct in the way in which they metabolize glucose. They also produce large quantities of a by-product called lactate. A protein called PK-M2 is a key mediator of glucose metabolism in cancer cells, and this year, Professor Adrian Krainer led a group including researchers at Harvard Medical School and The Broad Institute that discovered three molecular factors contributing to high levels of PK-M2 in cancer cells. PK-M2 is one of two isoforms, or slightly varying versions, of an enzyme called pyruvate kinase. A single gene called PK- M gives rise to both, via alternative splicing. Adrian’s expertise in splicing helped the team to understand how the benign isoform of the enzyme, PK-M1, is switched off and the dangerous M2 isoform is switched on in cancer cells. By manipulating three known splicing factors, the team was able to halt M2 production and separately to restore production of the benign M1 isoform. This sheds light on the so-called Warburg Effect and points to possible new targets for drugs that might reverse the pathological metabolism of cancer cells. How Blood Stem Cells Are Maintained in the Bone Marrow Niche Hematopoietic stem cells (HSCs) have unique abilities that are prized by medical researchers.

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